In general, I'd say no, not for the 8 bit systems, and I'm including the 8/16 bit 80C88 in that category. I've had DOS PCs on Ethernet and it wasn't much fun.
I don't think I've ever had an 8088 networked,
(I tell a lie - I once had the joys of installing Novell Netware on an IBM XT for an assignment) but I had a 286 hooked to my LAN for a while. There might be an exception to support Telnet, so you can run the SBC headless from a remote terminal and TFTP for loading/saving from memory. I don't see the benefits of host USB at all - its just more clutter on your bench to have a separate keyboard for the SBC, and there are better solutions for mass storage e.g. CF cards. Most anything else is going to run into driver issues to do anything useful.
The 68HC000 is a different matter. With a 32/16 bit processor and a 16MB address map, ucLinux is possible, and once you have a fully featured OS on there, USB and Ethernet make a lot more sense.
Your old 68HC000 topic for reference:
https://www.eevblog.com/forum/chat/i-pulled-the-plug-and-bought-a-mc68hc000-help/This 68008 project is worth a look for inspiration - though you have to contend with a 16 bit bus so a lot more wiring.
http://www.bigmessowires.com/68-katy/